Changes in city vertical profile as an indicator of sprawl: Evidence from a Mediterranean urban region

After the World War II the Mediterranean cities experienced important changes in their form becoming more compact and dense and then sprawling into larger areas. The complexity of causes and consequences involved in sprawl processes makes the classical models evaluating urban diffusion hardly applicable to the Mediterranean cities. Using descriptive statistics, regression analysis, and a Principal Components Analysis (PCA) this article investigates the changes (1920–2010) in the vertical profile of buildings in a traditionally compact urban region (Attica, Greece) taken as a paradigmatic example for hyper-dense cities in both developed and developing countries. The aim of this study is to illustrate how a widely-used indicator (the vertical profile of a city) may represent a proxy indicator of urban diffusion. The vertical profile of buildings has been changed in the investigated region towards densification with average building height passing from 1.3 floors in 1919 to 1.8 floors in 2009. However, both regression analysis and PCA revealed how the densification pattern has been shifting towards ‘horizontal’ rather than ‘vertical’ growth since the early 1990s. Low-density expansion areas possibly undergoing unsustainable land consumption and landscape fragmentation were identified according to the recent changes in the studied indicator. The findings illustrated in this article represent a potentially useful tool to monitor sprawl and the consequent land consumption in rapidly-changing urban landscapes.

► The increasing sprawl of Mediterranean cities has been observed since the early 1990s.
► Attica is considered an example of mono-centric, hyper-compact urban region.
► The vertical profile of buildings in Attica have increased densification during the last century.
► The vertical profile was correlated with the distance from the city centre until the 1990s.
► The city's vertical profile is a proxy for compactness and sprawl dynamics.